Calcium ATPase (PMCA or SERCA) (PMCA/SERCA)

Plasma membrane calcium ATPase (PMCA) and sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) are high-affinity ion transport enzymes belonging to the P-type ATPase family, responsible for active transport of Ca²⁺ out of the cytosol, using ATP hydrolysis. PMCA extrudes Ca²⁺ from the cell to tightly regulate intracellular calcium levels, especially in excitable tissues such as brain and muscle[1][3][5]. SERCA pumps move Ca²⁺ from the cytoplasm into the sarcoplasmic or endoplasmic reticulum, which is crucial for muscle relaxation and overall cellular calcium storage[8]. Both PMCA and SERCA require *magnesium as a cofactor* for ATPase activity but do not function as magnesium ion transporters; their dysfunction or altered expression is implicated in various pathologies, including heart failure, neurological diseases, and cancer[3][5][7][10]. Note: There is no recognized single enzyme known as “Calcium-magnesium adenosine triphosphatase.” The usage could represent a *misunderstanding* of Ca²⁺-ATPase cofactors (magnesium) versus transported substrates (calcium)[1][4][5]. For CDx, drug targeting, or database structuring, use "Plasma membrane calcium ATPase" or "Sarcoplasmic/endoplasmic reticulum calcium ATPase" as the *canonical* forms[1][5][10].

Other names

Calcium ATPaseCa²⁺-ATPasePlasma membrane Ca²⁺-ATPase (PMCA)Sarcoplasmic reticulum Ca²⁺-ATPase (SERCA)Secretory pathway Ca²⁺-ATPase (SPCA)

Inhibition of the ATPase prevents calcium efflux (PMCA) or reuptake into ER/SR (SERCA), disrupting calcium homeostasis and signaling. Modulation of ATPase activity alters intracellular calcium, affecting cell survival, contraction, or neurotransmitter release.